1. Field of the Invention
The present invention relates to a method and assembly for reducing the volume of a lung and, more particularly, to a mechanical lung volume reduction system comprising cords and anchors that pull on portions of a lung to compress the volume of a portion of the lung.
2. Background Information
The lungs deliver oxygen to the body and remove carbon dioxide. Healthy lung tissue includes a multitude of air passageways which lead to respiratory bronchioles within the lungs. These airways eventually lead to small sacs called alveoli, where the oxygen and carbon dioxide are exchanged through the ultra-thin walls of the alveoli. This occurs deep within the lungs, in an area which is accessed by a network of airways, consisting of a series of branching tubes which become narrower, shorter, and more numerous as they penetrate deeper into the lungs. As shown in FIG. 1, tiny air sacks called alveoli 1 surround both alveolar ducts 2 and respiratory bronchiole 3 throughout the lung. The alveoli are small, polyhedral recesses composed of a fibrillated connective tissue and surrounded by a few involuntary muscular and elastic fibers. These alveoli 1 inflate and deflate with air when we breathe. The alveoli are generally grouped together in a tightly packed configuration called an alveolar sac. The thin walls of the alveoli 1 perform gas exchange as we inhale and exhale.
During inhalation, as the diaphragm contracts and the ribs are raised, a vacuum is created in the chest, and air is drawn into the lungs. As the diaphragm relaxes, normal lungs act like a stretched balloon and rebound to the normal relaxed state, forcing air out of the lungs. The elasticity of the lungs is maintained by the supportive structure of the alveoli. This network of alveoli provides strength to the airway walls, as well as elasticity to the lungs, both of which contribute to the lung""s ability to function effectively.
Patients with pulmonary disease have reduced lung capacity and efficiency due to the breakdown of lung tissue. This often is caused by smoking. In cases of severe chronic pulmonary disease, such as emphysema, lung tissue is destroyed, reducing the strength of the airways. This reduction and strength of the airway walls allows the walls to become xe2x80x9cfloppyxe2x80x9d thereby losing their ability to remain open during exhalation. In the lungs of an emphysema patient, illustrated in FIG. 2, the walls between adjacent alveoli within the alveolar sac deteriorate. This wall deterioration is accelerated by the chemicals in smoke which affect the production of mucus in the lungs. Although the break down of the walls of the alveoli in the lungs occurs over time even in a healthy patient, this deterioration is greatly accelerated in a smoker causing the smoker""s lungs to have multiple large spaces 4 with few connecting walls in the place of the much smaller and more dense alveoli spaces 1 in healthy lung tissue.
A cross section of a diseased emphysematous lung will look like Swiss cheese due to the deterioration of the alveoli walls which leaves large spaces in the tissue. In contrast, a cross section of healthy lung tissue has few or no noticeable holes because of the small size of the alveoli. When many of the walls of the alveoli 1 deteriorate, as shown in FIG. 2, the lung has larger open spaces 4 and a larger overall volume, but has less wall tissue to achieve gas exchange.
In this diseased state, patients suffer from the inability to get the air out of their lungs due to the collapse of the airways during exhalation. As a result, heavily diseased areas of the lung become over-inflated with the air that cannot escape due to the collapse of the airways. This air remains in the lung and is non-functional as it does not aid in the blood-gas exchange process. Because the lungs are limited to the confines of the chest cavity, this over-inflation restricts the in-flow of fresh air and hampers the proper function of healthier tissue. As a result of the over-inflation, patients experience significant breathlessness. Thus, the emphysema patient must take in a greater volume of air to achieve the same amount of gas exchange as a healthy individual. However, individuals suffering from emphysema still have insufficient gas exchange even when they take in as much air as their chest cavity can accommodate. Emphysema patients will often look barrel-chested and their shoulders will elevate as they strain to make room for their over-inflated lungs to work.
In cases of severe emphysema, lung volume reduction surgery (LVRS) improves lung efficiency of the patient and allows the patient to regain mobility. In lung volume reduction surgery, a diseased portion of an emphysematous lung having a large amount of alveolar wall deterioration is surgically removed as illustrated in FIG. 3. LVRS is performed by opening the chest cavity, retracting the ribs, stapling off, and removing the more diseased portion of the lung 31. This allows the remaining healthier lung tissue to inflate more fully and take greater advantage of the body""s ability to inhale and exhale. Since there is more inspired air there is increased gas exchange in the healthier portion of the lung. As a result lung efficiency improves.
Lung volume reduction surgery is an extremely invasive procedure requiring the surgical opening of the chest cavity and removal of lung tissue. This surgery has substantial risks of serious post-operative complications, such as pneumothorax, and also requires an extended convalescence.
Accordingly, it is desirable to achieve the benefits of improved air exchange for emphysema patients provided by LVRS without invasive open chest surgery and the associated complications.
The present invention relates to a lung volume reduction device comprising at least one anchor having a reduced profile and being configured to assume an expanded profile wherein in the reduced profile the anchor is capable of being advanced into an airway of the lung and in the expanded profile the anchor secures to lung tissue, the anchor having at least one connector, at least one cord having a proximal end and a distal end, the proximal end being attached to at least one of the connectors and the distal end being attached to at least one of the anchors, and a delivery device being configured to removably seat at least one of the anchors on a distal end.
The present invention includes an anchor for use with the lung volume reduction device where the anchor comprises a central portion and an attachment portion connected to the central portion, the attachment portion being moveable between a reduced profile and an expanded profile, wherein when in the reduced profile the anchor is capable of being advanced into a passageway of the lung and when in the expanded profile the attachment portion attaches to the lung; and at least one cord having a distal end and a proximal end, the distal end being attached to the central portion of the anchor and the proximal end secured to the connector.
A variation of the invention includes an anchor comprising a wire where rotation of the anchor in a lung passageway permits ends of the wire to contact lung tissue causing the anchor to assume an expanded profile.
Another variation of the invention includes an anchor comprising a segment having a first and second end, wherein the central portion of the anchor is located between the first and second ends, the first end may be configured to be atraumatic and the second end may be configured to penetrate lung tissue, wherein rotation of said anchor in the lung passageway permits the ends to contact lung tissue causing the anchor to assume the expanded profile.
Another variation of the invention includes an anchor comprising a flat spring, the ends of the spring comprising the attachment portion, the spring folded about a center point, the fold forming the central portion of the anchor.
Another variation of the invention includes an anchor with an attachment portion comprising at least one tine, each the tine having a first end and a second end, the first end being attached to the central portion, wherein when the second ends of the tine moves away from the central portion the anchor assumes the expanded profile. The invention may include varying the number of tines as needed, for example, two, three, or four tines may be used.
The invention further includes providing a fibrosing agent on an anchor. The fibrosing agent may be, for example, on a surface of the anchor or adjacent to the attachment portion of the anchor.
Another variation of the anchor includes sizing the anchor so that it may enter an airway of less than 3 mm in approximate diameter. The inventive anchor may include tines is configured to prevent movement of the anchor relative to the airway when the anchor is in the expanded profile. The anchor may be configured to be atraumatic to the lung.
Another variation of the invention includes an anchor that is mechanically deformable to assume the expanded profile. In another variation, an anchor may be comprised of a shape memory alloy and the anchor is thermally deformable to assume the expanded profile. A variation of the anchor may also include one that is spring biased to assume the expanded profile.
Another variation of the invention includes an anchor with a the cord further comprising a wedge attached to a distal end of the cord, and where there are at least two tines, and the wedge being slidably attached to the anchor between at least two of the tines, when the wedge is proximate to the second end of the tines the anchor is in the reduced profile, and when the wedge slides towards the central portion of the anchor, the wedge displaces the tines so that the anchor assumes the expanded profile. This variation may also include stops that fixedly attach the wedge adjacent to the central portion.
Another variation of the invention includes an anchor that further comprises at least one covering having a wall, the wall having a plurality of openings, the covering being placed over the central portion, the second end of the tine extending through the openings of the covering, wherein movement of the central portion within the covering advances or retracts the second end of the tine through the openings.
Another variation of the invention includes a cord as previously described further including a hook attached to a proximal end of the cord.
Another variation of the cord includes a cord comprised from an elastic material, and/or a cord comprising a tube having a lumen. Another variation of the cord includes a cord having at least two segments having different diameters.
The present invention also includes a delivery device for use with the lung volume reduction device where the delivery device comprises an elongate member having a distal and a proximal end, the elongate member being sized to advance within the airway of the lung, the elongated member being configured to removably seat the anchor on a distal end of the elongated member.
A variation of the invention includes a delivery device with an elongated member further comprising a fluid delivery port at a proximal end of the elongated member, a lumen extending between the proximal and distal ends of the elongated member, and a seal in the lumen at the proximal end, the seal configured to allow the cord to exit from the proximal end while keeping the lumen fluidly sealed at the proximal end.
Another variation of the invention includes a delivery device where the distal end of the elongated member comprises a tapered section, the distal end being configured so that retracting the anchor in a proximal direction over the tapered section causes the anchor to expand to assume the expanded profile.
A variation of the delivery device may also include a distal end comprising a compressible sleeve located between the anchor and the elongate member, compressing the sleeve in a lengthwise direction causes the sleeve to expand to an increased diameter, expansion of the sleeve to the increased diameter mechanically deforms the anchor to assume the expanded profile.
Another variation of the invention may include a delivery device comprising a cutter being configured to severe a cord. The cutter may include a suture cutter, a blade within the elongated member, a flexible rod having a sharpened end, a heating element, and/or a first and second shearing surfaces.
In one variation of a cutter having a first and second shearing surfaces, the elongate member may comprise the first shearing surface and the second shearing surface may be moveable within the elongated member such that the section of the cord between the first and second shearing surfaces is cut as the shearing surfaces join. A variation of the invention includes a cutter configured such that the second shearing surface moves at least axially or at least torsionally within the elongate member.
The present invention also includes a connector for use with the lung volume reduction device comprising a body having at least one passageway sized to permit passage of the cord, and a stop having at least a portion connected to each of the passageways the stop configured to prevent movement of the cord after the cord is fed through the passageway to a desired location.
A variation of the invention may include a connector as described above wherein the body is plastically deformable such that deformation of the body reduces a diameter of the passageway to create the stop.
Another variation may include a connector wherein the stop comprises at least one tapered plug having a first and second diameters and at least one ring having an inner diameter sized between the first and second diameters of the plug, the ring located co-axially with each of the passageways, wherein movement of the at least one cord may be prevented by passing the at least one cord through the ring and inserting the tapered plug into the ring.
Another variation of the connector may include a tube removably located within the passageway of the connector where the tube permits passage of the cord. In one variation, the connector may have a plurality of stops and removal of the tube allows the stops to frictionally hold the cord within the connector. In another variation, the connector may have a moveable section having a hole sized to permit passage of the cord, the moveable section having an aligned position such that the hole is in alignment with the passageway which allows movement of the cord, and a non-aligned position such that the hole is not in alignment with the passageway which prevents movement of the cord. In this variation, the moveable section may be biased to assume the non-aligned position. In this variation, the tube may be used to retain the moveable section in the aligned position.
Another variation of the invention includes a connector having body comprised of a spring having a plurality of turns, the plurality of turns comprising the stops where the at least one cord is woven through at least one of the turns, wherein the spring has an relaxed state where the turns compress against the cord to prevent movement of the cord.
In another variation of the invention, the stop of the connector comprises a section of reduced diameter in the passageway. The connector may further include a flange within the passageway, the flange having a plurality of slots radially extending from a central opening, wherein the center opening comprises the section of reduced diameter and is sized to permit movement of the cord and the slots are sized to prevent movement of the cord. Another variation of the invention may include a connector having a stop which further comprises a plug which seats in the section of reduced diameter to provide frictional resistance against the cord to prevent movement of the cord. The plug may be directionally biased towards the section of reduced diameter by a spring.
Another variation of the invention may include a connector as described above wherein the passageway further comprises a plurality of prongs extending away from the body towards a center of the passageway, the prongs configured to retain the proximal end of the cord or to interfere with the cord and hold it in place by frictional forces.
Another variation of the invention may include a connector as described above wherein the stop of the connector comprises a stopper slidably located within the passageway and attached to the body by a spring element such that the stopper is maintained in the passageway and is temporarily moveable out of a proximal end of the body, the stopper having a proximal diameter less than a diameter of the passageway, wherein after a segment of increased diameter of a cord is pulled from a distal end of the body through the proximal end of the body and past the stopper, the stopper prevents substantial movement of the cord in a distal direction.
The invention further includes a method for minimally invasively or non-invasively treating a lung having at least an emphysematous portion comprising the step of improving a pulmonary function of at least a first portion of the lung. Improving a pulmonary function of at least a first portion of the lung may include reducing hyperinflation of a second portion of the lung, increasing the range of motion of the diaphragm, redirecting airflow to a healthier portion of the lung, and/or reducing a volume of a second portion of the lung to remove non-functional residual air from the lung.
Another variation of the invention includes a method a method for minimally invasively or non-invasively treating a lung having at least an emphysematous portion comprising the step of improving a pulmonary function of at least a first portion of the lung wherein the step of improving a pulmonary function of at least the first portion of the lung comprises the steps of attaching a first anchor to the lung, attaching a second anchor to lung, connecting a cord between the second anchor and the first anchor; and shortening the length of the cord between the first and second anchors to compress a second portion of the lung. The method may include the step of deflating at least a portion of the lung prior to the shortening step. The method may include the step of injecting a sclerosant agent in the second portion of the lung to maintain compression of the second portion. And, the connecting step described above may include using a connector to join separate cords of the first and second anchor.
The invention also includes the method described above with the additional step of placing at least one support member in the lung to create an area of improved anchor support for increasing the ability of the anchors.
The invention also includes a lung volume reduction device kit comprising the lung volume device as described above and a bronchoscope, and/or a fibrosing agent.
The invention also includes a method for preparing the lung volume reduction device described above for use in a medical procedure comprising the steps of sterilizing the lung volume reduction device, and packaging the lung volume reduction device.
The invention also includes a method of teaching the use of any of the devices or methods described herein.